/* Page scaffolding: containers, the header/footer frame, and vertical rhythm. */

/* --- Containers ----------------------------------------------------------- */

.container {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.container--narrow {
  max-width: var(--container-narrow);
}

/* Body copy is capped at a readable measure even inside a wide container.
   Applied to the children so full-bleed elements can opt out. */
.prose > * {
  max-width: var(--measure);
}

.prose > .lede {
  max-width: var(--measure-narrow);
}

/* --- Page frame ----------------------------------------------------------- */

body {
  display: flex;
  min-height: 100vh;
  min-height: 100svh;
  flex-direction: column;
}

main {
  flex: 1;
  /* -1px prevents the focus ring being clipped when the skip link lands here. */
  outline-offset: -1px;
}

.page {
  padding-block: var(--space-xl) var(--space-2xl);
}

/* --- Header --------------------------------------------------------------- */

.site-header {
  position: sticky;
  inset-block-start: 0;
  z-index: 10;
  background: color-mix(in srgb, var(--ground) 92%, transparent);
  border-block-end: 1px solid var(--rule);
  /* Falls back to the solid colour above where backdrop-filter is unsupported. */
  backdrop-filter: blur(8px);
}

.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-m);
  padding-block: var(--space-s);
}

/* --- Footer --------------------------------------------------------------- */

.site-footer {
  margin-block-start: var(--space-2xl);
  padding-block: var(--space-l);
  border-block-start: 1px solid var(--rule);
  background: var(--surface-sunk);
  color: var(--ink-muted);
  font-size: var(--text-sm);
}

.site-footer__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-s) var(--space-l);
}

.site-footer p {
  margin: 0;
}

/* --- Generic grids --------------------------------------------------------
 * auto-fit + minmax means no breakpoint is needed: the columns reflow when
 * the content stops fitting, which is the only moment that actually matters.
 */

.grid {
  display: grid;
  gap: var(--space-m);
  grid-template-columns: repeat(auto-fit, minmax(min(18rem, 100%), 1fr));
}

.grid--wide {
  grid-template-columns: repeat(auto-fit, minmax(min(24rem, 100%), 1fr));
}

.stack > * + * {
  margin-block-start: var(--space-s);
}

.stack--loose > * + * {
  margin-block-start: var(--space-l);
}

/* --- Full-bleed band ------------------------------------------------------ */

.band {
  padding-block: var(--space-xl);
  background: var(--surface-sunk);
  border-block: 1px solid var(--rule);
}

.band--plain {
  background: transparent;
  border: 0;
}

/* --- Small screens -------------------------------------------------------- */

@media (max-width: 47.99em) {
  .site-header__inner {
    flex-wrap: wrap;
    row-gap: var(--space-xs);
  }

  /* Collapsed by default; nav.js reveals the toggle and adds the open state.
     Without JS the rule below keeps the nav visible — see components.css. */
  .site-nav--collapsible {
    order: 3;
    flex-basis: 100%;
  }
}